It's set after the completion of SGRUB, and follows Eridan's mishaps when he accidentally falls off his ship's rigging and dies. However, he doesn't stay dead, and comes back to life shorty after as a Rainbow Drinker.
Immediately contacting Kanaya, he broaches the subject of his newfound Rainbow Drinkerness, and, after a short discussion about fashion and claiming Kanaya infected him, she eventually gives him advice that amounts to 'You Can Live Quite Comfortably On One Or Two Donors With Hearty Constitutions' and Eridan (quite logically) decides that Equius is the best candidate for the job.
- Accidental Murder: Kanaya warns Eridan that his new hunger could lead to him accidentally killing people, and finding a donor is therefore imperative. She then casually mentions it would also help to prevent her from killing him again.
- Back from the Dead: Technically, Eridan has died twice; once in SGRUB when Kanaya killed him, and then post-SGRUB when he falls off his ship's rigging. This is also why he assumes Kanaya infected him with her Rainbow Drinker traits since she killed him the first time.
- Bizarre Alien Biology: Dying makes you come back as a glowing sun-proof vampire.
- Badass Cape: Eridan, obviously.
- Hypnotic Eyes: In universe. Eridan wonders if the stories about Rainbow Drinkers having this ability is true, and is eager to try it at one point.
- If You Ever Do Anything to Hurt Her...: Genderflipped, but Nepeta more or less makes a violent promise to Equius that if Eridan does anything to harm him...if he hurts you, i'll gut him
- Must Be Invited: A play on this typical vampire trope when Eridan visits Equius, as he playfully flirts with Equius about this until the blueblood outright invites him into his hive.
- Ninja Pirate Zombie Robot: Eridan kinda turns into this, as he's now an undead Rainbow Drinker Seadweller space alien with the ability to blow things up with Hope.
- Noodle Incident: Eridan goes swimming for his dinner shortly after coming back as a Rainbow Drinker.You swim for your supper. It is an arduous and frankly undignified affair that includes an octopus, a fat seal, and a fistfight with a shark. You don't want to talk about it.
- Our Vampires Are Different: They're immune to sunlight damage and can still be seen in mirrors. Eridan also has no issue with entering water.
- Rule of Cool: When Equius opens his door for Eridan, he's fairly baffled at how Eridan managed to snag exactly the right spot to make his cape billow behind him dramatically.
- Smells Sexy: Due to his new Rainbow Drinker state, Eridan gets immensely distracted by Equius' smell when he first visits him. Probably doesn't help that Equius naturally sweats a lot.
- Super Strength: Equius, obviously. He still manages to be a threat to Eridan and bruises his sternum by accident.
- Undignified Death: Eridan managed to get through most of SGRUB and facing the Black King without dying, and is later killed by an undead alien vampire. Then he promptly dies again post game from falling off something.
- Unequal Pairing: Not really, but Equius himself gets fairly giddy at times due to Eridan being a highblood Seadweller since he's such a brown-noser for the caste system and already having 'things' about authority.
- Weakened by the Light: Averted, as being a Rainbow Drinker now makes Eridan immune to the harsh and potentially lethal effects of the Alternian sun. It's also one of the first things he notices when he wakes up after dying, as he's outside in the sunlight without being roasted alive.